This invention relates to steering and propulsion means for ships or other vessels.
Steering and propulsion means for ships and other vessels are known which are mountable in the bottom of a vessel and which are adapted to draw in water through an inlet opening which is usually in the bottom of the vessel and discharge the water, under pressure, through an outlet in the bottom of the vessel, the outlet comprising deflector means adapted to discharge the water under pressure as a stream or jet which will provide thrust having a substantially horizontal component, the deflector means being rotatable through 360.degree. so that said stream or jet can be directed as required to provide both propulsion and steering. In smaller vessels such as barges and small ferries, such steering and propulsion means will generally be mounted at or towards the stern of the vessel and provide the sole means of propulsion and steering. In larger vessels, the steering and propulsion means will generally be mounted at or towards the bow of the vessel and will generally only be used during maneuvers at slow speed, e.g., when docking or berthing the vessel. Such a steering and propulsion means will hereinafter be referred to as "a steering and propulsion means of the kind described."
Known steering and propulsion means of the kind described have generally comprised a hollow casting defining a passage substantially in the form of an inverted "U," one end of the passage communicating with said inlet opening and the other end of the passage communicating with said outlet, suitable pump means being mounted in said passage for drawing water in through said inlet opening and discharging it, under pressure, through said outlet. Two shafts extend into said casing through suitable glands, one being a drive shaft one end of which is connected to said pump means and the other end of which is connectable to a suitable prime mover, and the other being a steering shaft, one end of which is connected to said deflector means and the other end of which is connectable to suitable steering control means. Examples of prior patents illustrating propulsion units are U.S. Pat. Nos. 3,800,731 and 3,543,713.
The known steering and propulsion means of the kind described are efficient in use, but suffer from the disadvantage that they are large in size and the casings thereof are large and complex in shape and therefore expensive to produce, whether by casting or by fabrication.